Friday 20 March 2009 07.21 EDT
First published on Friday 20 March 2009 07.21 EDT

Nearly one-third of US birds are endangered, threatened or in significant decline, according to a government conservation report.

It says the findings are "a warning signal of the failing health of our ecosystems" and reports that birds in Hawaii, the most bird-rich state, are "in crisis".

The authors say that energy production deriving from wind, ethanol and mountain-top coal mining is contributing to steep drops in bird populations.

The State of the Birds report chronicles a four-decade decline in many of the country's bird populations and provides many reasons for it, from suburban sprawl to the spread of exotic species to global warming.

In the last 40 years, populations of birds living on prairies, deserts and at sea have declined between 30-40%.

But in almost every case, energy production has also played a role.

Environmentalists and scientists say the report should encourage the Obama administration to act cautiously as it seeks to expand renewable energy production and the electricity grid on public lands, and tries to harness wind energy along the nation's coastlines.

"We need to go into these energies with our environmental eyes open," said John Fitzpatrick, the director of the Cornell laboratory of ornithology, which helped draft the report along with non-profit advocacy groups. "We need to attend to any form of energy development, not just oil and gas."

Many of the bird groups with the most rapid declines in the last 40 years inhabit areas with the greatest potential for energy development.

Among the energy-bird conflicts cited by the report:

• More than half of the monitored bird species that live on prairies have experienced population losses. These birds, such as the lesser prairie chicken, are threatened by farmers converting grasslands into corn fields to meet demand for biofuels

• In the Arctic, where two-thirds of all shorebirds are species of concern, melting ice brought about by climate change could open up more areas to oil and gas production. Studies show that trash near drilling rigs attracts gulls that prey on other species

• Mountain-top coal mining in Appalachia clears patches of forest contributing to the decline of birds like the Cerulean warbler that breeds and lives in treetops

• Hawaii is home to one third of all US listed bird species. Seventy-one species have gone extinct on the islands since humans colonised them in 300AD and the report states that at least 10 more species may have gone extinct in recent times. "Proven conservation measures are urgently needed to avert this global tragedy, including increasing investment in protecting remaining forests, eliminating exotic predators and captive breeding," the report says

The report, released by the interior secretary Ken Salazar on Tuesday, was requested in October 2007 by the then president, George W Bush.

The report did not indicate which form of energy production was the most detrimental.